diff options
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp b/llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp index 2e4707f916d..c1d3f925515 100644 --- a/llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp +++ b/llvm/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp @@ -562,20 +562,28 @@ Vectorizer::getVectorizablePrefix(ArrayRef<Instruction *> Chain) { if (BarrierMemoryInstr && OBB.dominates(BarrierMemoryInstr, MemInstr)) break; - if (isa<LoadInst>(MemInstr) && isa<LoadInst>(ChainInstr)) + auto *MemLoad = dyn_cast<LoadInst>(MemInstr); + auto *ChainLoad = dyn_cast<LoadInst>(ChainInstr); + if (MemLoad && ChainLoad) continue; + // We can ignore the alias if the we have a load store pair and the load + // is known to be invariant. The load cannot be clobbered by the store. + auto IsInvariantLoad = [](const LoadInst *LI) -> bool { + return LI->getMetadata(LLVMContext::MD_invariant_load); + }; + // We can ignore the alias as long as the load comes before the store, // because that means we won't be moving the load past the store to // vectorize it (the vectorized load is inserted at the location of the // first load in the chain). - if (isa<StoreInst>(MemInstr) && isa<LoadInst>(ChainInstr) && - OBB.dominates(ChainInstr, MemInstr)) + if (isa<StoreInst>(MemInstr) && ChainLoad && + (IsInvariantLoad(ChainLoad) || OBB.dominates(ChainLoad, MemInstr))) continue; // Same case, but in reverse. - if (isa<LoadInst>(MemInstr) && isa<StoreInst>(ChainInstr) && - OBB.dominates(MemInstr, ChainInstr)) + if (MemLoad && isa<StoreInst>(ChainInstr) && + (IsInvariantLoad(MemLoad) || OBB.dominates(MemLoad, ChainInstr))) continue; if (!AA.isNoAlias(MemoryLocation::get(MemInstr), |
